Control signaling for wireless communication

ABSTRACT

In accordance with an example embodiment of the present invention, a method comprises allocating a control channel resource in a wireless relay transmission frame on a wireless relay link; generating a control signaling based on at least one of a resource allocation scheme, a status of the wireless relay link and a traffic condition of the wireless relay link; mapping the control signaling to the allocated control channel resource via at least one of a time-first mapping, a frequency-first mapping, and a multiplexing mapping; and transmitting the control signaling in the allocated control channel resource on the wireless relay link to at least one associated relay node.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/934,226, filed Mar. 23, 2018, which is a continuation of U.S. patentapplication Ser. No. 14/725,526, filed May 29, 2015, which issued onApr. 3, 2018, as U.S. Pat. No. 9,936,484, which is a continuation ofU.S. patent application Ser. No. 14/021,622, filed Sep. 9, 2013, whichissued on Jun. 2, 2015 as U.S. Pat. No. 9,048,989, which is acontinuation of U.S. patent application Ser. No. 12/390,267, filed Feb.20, 2009, which issued on Sep. 10, 2013 as U.S. Pat. No. 8,532,015,which is incorporated by reference as if fully set forth.

TECHNICAL FIELD

The present application relates generally to methods and apparatuses fortransmitting control signaling over a wireless relay link to supportextended coverage and improved quality of service.

BACKGROUND

To help achieve extended network coverage, improve service quality, andprovide services such as wireless broadcast TV on user equipments,wireless relay links are being developed for a new generation of networktechnologies such as 4th generation (4G) wireless networks. A wirelessrelay link is a wireless connection between a radio access node and arelay node so that the access node may be coupled to an end user deviceor user equipment via the relay node. Otherwise the user equipment maybe out of the reach of the access node or receive a poor-quality servicefrom the access node.

Control signaling is a part of a wireless relay link because it enablescommunications between the access node and the relay node. The accessnode may send control instructions such as an access grant, atransmission acknowledgement, and a negative transmissionacknowledgement, among others, to the relay node via the controlsignaling. With control signaling, a connection may be set up betweenthe access node and the relay node, resource may be allocated, atransmission error between the two may be detected and corrected. Thecontrol signaling may take place at any one of the layers of open systeminterconnection (OSI) network model, including the physical layer, alsotermed layer 1, the data link and radio link control layer, also termedlayer 2, and the network layer, also termed layer 3.

Although there are some existing control signaling schemes for wirelesstechnologies based on standards such as IEEE 802.16 standards andexisting 3^(rd) generation partnership project (3GPP) standards, theexisting control signaling schemes do not meet the needs of a newgeneration of wireless technologies such as 4G networks to support newgeneration of wireless services such as broadcast TV on user equipments.

SUMMARY

Various aspects of examples of the invention are set out in the claims.

According to a first aspect of the present invention, a method comprisesallocating a control channel resource in a wireless relay transmissionframe on a wireless relay link; generating a control signaling based onat least one of a resource allocation scheme, a status of the wirelessrelay link and a traffic condition of the wireless relay link; mappingthe control signaling to the allocated control channel resource via atleast one of a time-first mapping, a frequency-first mapping, and amultiplexing mapping; and transmitting the control signaling in theallocated control channel resource on the wireless relay link to atleast one associated relay node.

According to a second aspect of the present invention, an apparatuscomprises an upper-layer control module configured to allocate a controlchannel resource in a wireless relay transmission frame on a wirelessrelay link, and to generate a control signaling based on at least one ofa resource allocation scheme, a status of the wireless relay link and atraffic condition of the wireless relay link. The apparatus alsocomprises a physical-layer control module configured to map the controlsignaling to the allocated control channel resource via one of atime-first mapping, a frequency-first mapping, and a multiplexingmapping; and to transmit the control signaling in the allocated controlchannel resource on the wireless relay link to at least one associatedrelay node.

According to a third aspect of the present invention, An apparatuscomprises a control module configured to determine a decoding set for areceived wireless relay transmission frame; and to determine a startingpoint and a length of a control signaling. The apparatus also comprisesa decoding module configured to decode the received wireless relaytransmission frame received from an associated wireless access node; todetect a beginning of the control signaling embedded in the wirelessrelay transmission frame based on the decoding set; and to extract thecontrol signaling from the decoded wireless relay transmission frameusing the starting point and the length of the control signaling.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of example embodiments of the presentinvention, reference is now made to the following descriptions taken inconnection with the accompanying drawings in which:

FIG. 1 illustrates an example wireless relay system;

FIG. 2 illustrates an example embodiment of a wireless access node;

FIG. 3 illustrates an example of a partial wireless relay transmissionframe;

FIG. 4 illustrates an example method for transmitting control signalingon a wireless relay link;

FIG. 5 illustrates an example embodiment of multiplexing multiplecontrol signalings into a wireless relay transmission frame on a relaylink;

FIG. 6 illustrates an example embodiment of updating controlconfiguration on a wireless relay link;

FIG. 7 illustrates an example embodiment of a wireless relay node; and

FIG. 8 illustrates an example method for decoding the control signaling.

DETAILED DESCRIPTION

Among the challenges to be address by the present disclosure is thedevelopment of methods and apparatus that may efficiently allocatecontrol channel resource in a wireless relay transmission frame and mapthe control signaling to the allocated control channel resource in aflexible manner to accommodate different traffic conditions fordifferent wireless services. Another challenge is to make the controlsignaling on the relay link backward compatible so that the existingnetwork nodes and user equipments (UEs) may not be retooled to supportthe new control signaling.

FIGS. 1 through 8, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the invention. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any type of suitably arranged device or system.

FIG. 1 illustrates an example wireless relay system. The examplewireless relay system 100 includes one wireless access node 200 and arelay node 700. The wireless access node 200 may be located in awireless cell 102 and is coupled to a transmission tower 112. The relaynode 700 may be located in an adjacent relay cell 104 and coupled toanother transmission tower 112. The wireless access node 200 may includea relay control signaling module 210 and communicate with the relay node700 via a wireless relay link 106. In a way, the wireless relay node 700may be viewed as an extension to the access node 200 to reach an enduser equipment 108 which may be a mobile station. The access node 200may communicate with the relay node 700 at layers that may include butnot limited to the physical layer, data link layer and network layer,which are also referred to as layer 1, layer 2 and layer 3 in the OSInetwork model. More details of the access node 200 are illustrated inFIG. 2 and described hereinafter. More details of the relay node 700 areillustrated in FIG. 700 and described hereinafter.

In one embodiment, the wireless access node 200 may be a long termevolution (LTE) radio access node (eNodeB) and the relay node 700 may bea 3^(rd) generation project group (3GPP) access node (NodeB). In such anembodiment, an eNodeB in the cell 102 may extend to the relay node 700,and this communication at the layer 3 between the cell 102, also calleddonor cell, and the relay node 700 is also called layer 3 relay orself-backhauling. The “layer 3 relay” node may be an eNodeB supportingone or more cells of its own. The layer 3 relay node is accessible toLTE Release 8 user equipments and provides a downlink control signaling.The control signaling contents may include a control instruction on aprimary synchronization channel (P-SCH), a secondary synchronizationchannel (S-SCH), a physical broadcast channel (P-BCH) and a commonreference signal (CRS). The P-SCH and S-SCH channels may be used tosynchronize an end user equipment with the associated network after apower up. A P-BCH channel may be used to broadcast common controlinformation such as network parameter settings to all associated userequipments which are synchronized to the network. A CRS may betransmitted by an eNodeB to associated end user equipments in itscoverage, for the purpose of channel measurement and channelsynchronization to allow the UEs to access a layer 3 relay cell such asthe relay cell 104. In one embodiment, the layer 3 relay node, afterbeing connected wirelessly with the eNodeB such as the access node 200,may provide same service to end users in its converge, just as an eNodeBmay. The layer 3 relay node such as the relay node 700 may have awireless connection to eNodeB, in order to reach an associated corenetwork. The relay node 700 is wirelessly coupled to other part of aradio access network via a donor cell 114, which may typically provide alarger coverage.

The control signaling between the access node 200 and the relay node 700may be carried on the wireless relay link 106 and may be either aninband control signaling or outband control signaling. An inbandsignaling is carried on a wireless link between the two nodes using thesame frequency band. An outband signaling may use a relay link that usesa frequency band that is different from that of the access node 200. Theoutband resources with a powerful amplifier for the eNodeB layer 3 relaylink may make the backhaul link an add-on to eNodeB. But the outbandresource may use a designated spectrum and thus complicate networkdeployments due to different spectrum allocations in differentcountries. Thus the relay link using outband resource may add additionalcost and also to the donor cell 114. The present disclosure focuses onthe inband control signaling that may achieve significant link gains viaantenna tilting and adequate positioning of the relay node and areduction of shadowing loss. A shadowing loss may be a large-scalefading loss of wireless channel and may change with the location of thetransmitter and the receiver of the access node. The shadowing loss ingeneral may not change very frequently and may be modeled as a randomvariable with variance up to several decibels. Usable bandwidth for theself-backhauling may depend on the number of user equipments (UEs)coupled to the layer 3 relay node and the traffic load on the relaylink.

FIG. 2 illustrates an example embodiment of a wireless access node 200.The wireless access node 200 may include a relay control signalingmodule 210. The relay control signaling module 210 may include anupper-layer control module 214 and a physical-layer control module 216.The wireless access node 200 may also include a collection 220 of othercomponents of the access node 200. Examples of the other components mayinclude air interface module and a power module.

The upper layer control module 214 may be configured to determine astarting point in a wireless relay transmission frame for carrying acontrol signaling and a length of the control signaling. The upper layercontrol module 214 may also be configured to allocate wireless channelresource for the wireless relay link to carry payload data and thecontrol signaling, using one of resource allocation schemes. Theresource allocation scheme may be a semi-static, dynamic, or hybridresource allocation. A semi-static scheme allocates a relay link for arelatively longer time period before a change takes place, for example,for a few seconds, to accommodate relatively stable traffic pattern. Thedynamic resource allocation scheme may allocate the relay link on adynamic basis, for example, on a millisecond basis, to accommodate amore dynamic traffic pattern. One effect of the dynamic resourceallocations may be for a better accommodation of fast traffic change andalso for a potential scheduling gain over fast fading of wirelesschannels. The hybrid resource allocation scheme is a mix of the dynamicresource allocation and the static resource allocation. The upper layercontrol module 214 may also be configured to generate a controlsignaling based on at least one of a resource allocation scheme, astatus of relay link, a traffic condition in the relay node, and/or thelike. The upper layer control module 214 may be located at a layer abovethe data link layer or the layer 2 and may be at the network layer, orlayer 3 of the OSI model.

The physical-layer control module 216 may be configured to locate astarting point of the control signaling within the wireless relaytransmission frame and map a control signaling to one or more allocatedcontrol signaling resources. The physical-layer control module 216 maytransmit control signaling on the wireless downlink to the relay node700. The downlink control signaling may include resource grants,acknowledgement and negative acknowledgement to a transmission from therelay node 700. The physical-layer control module 216 may be configuredto map the control signaling to the allocated control channel resourcevia one of a time-first mapping, a frequency-first mapping, amultiplexing mapping and/or the like. The physical-layer control module216 may be configured to transmit the control signaling to multipleassociated relay nodes at the same time.

The collection 220 of other components may include air interface module,a power module, and other modules that make up the wireless access node200. Examples of the other modules may include a radio frequency module,a transceiver module, a baseband signal processing module. The radiofrequency module may turn a baseband signal into a radio frequency band.The transceiver module with at least one antenna set may transmit andreceive the radio signals, and the baseband signal processing module mayperform coding, modulation and other signal processing.

FIG. 3 illustrates an example of a partial wireless relay transmissionframe 300 to illustrate an example of resource allocation for thecontrol signaling on a wireless relay link. The example of the partialwireless relay transmission frame 300 shows three physical resourceblocks (PRBs), e.g., PRB1 304, PRB2 306, and PRB3 308 respectively. APRB may contain a number of control channel elements (CCEs). In oneembodiment, a portion 302 of the PRBs is the part of the wireless relaytransmission frame 300 that is used for carrying the control signaling.The portion 302 may otherwise be left unused if not used to carry therelay control signaling. One embodiment of the wireless relaytransmission frame may be a multicast/broadcast over single frequencynetwork (MBSFN) sub-frame as specified in the LTE Release 8. The MBSFNsub-frame may be used to support service feature such as broadband TV onhandsets. In some cases, the resources on transmission frame may not befully utilized due to a variety of reasons. For example, LTE Release 8compliant UEs may ignore the last several symbols, e.g., 10 symbols, ina 1-millisecond (ms) MBSFN sub-frame. In addition to the regular 1-msMBSFN sub-frame, there is another type of MBSFN sub-frame with zerocontrol symbols, or zero-control-symbol MBSFN sub-frame, that may notcarry any control symbols or reference signals. For example, LTE Release8 compliant UEs may not expect and thus may not process any controlsignaling or reference signals after receiving a zero-control-symbolMBSFN sub-frame. However, the relay control signaling module 210 of FIG.2 may accommodate both the regular MBSF sub-frame and thezero-control-symbol MBSFN sub-frame for the control signaling on therelay link 106.

One embodiment of the wireless relay transmission frame 300 is an MBSFNsub-frame for which three PRBs, for example, PRB1 to PRB3 may beallocated for the relay link. There is a total of nine symbols availablein the MBSFN sub-frame for carrying the control signaling. For example,a starting point of control channel resource, Ps in FIG. 3, isdetermined by a combination of 1) the index of the first symbolavailable for the relay link, 2) the index of PRB1. These two parametersmay be configured by the upper layer control module 214 in a semi-staticfashion in order to simplify the implementation and complexity ofresource allocation and also to reduce the total control signalingoverhead. The size of the CCEs in the example is assumed to contain twoadjacent symbols within PRB1 304, as shown in the FIG. 3. However, theactual size of CCEs within a PRB may be further optimized according tothe quality of relay link and the content of the control signaling. Thenumber of symbols that may be used for control signaling is determinedby Pt as in the FIG. 3. For example, if Ps is at symbol k, the symbolsfrom k to Pt, represented as Δk, may be used for control signaling,where Pt=k+Δk. Δk may be indicated by the control signaling transmittedin relay sub-frame. To simplify the detection by the receiving relaynode 700, this “indication information” may be mapped to a pre-definedtime/frequency resource. For example, it may be transmitted in the firstCCE, e.g., CCE1, as shown in FIG. 3.

In one embodiment of the wireless relay transmission frame 300, thecontrol channels may be mapped to the CCEs, e.g., CCE1, CCE2, and CCE3in a time-first fashion. As a result, when the symbol index reaches Pt,the CCE on the next PRB may be mapped to the control signaling. Afterthe control signaling is mapped to the control channel elements, thepayload data may be mapped to the PRBs which contain at least onecontrol CCE, and the range of data symbols may start at Ps and end atthe maximum number of symbol available in the MBSFN sub-frame on therelay link. In another embodiment, the access node 200 may decide theparameter Pt based on at least two parameters: 1) a total number ofcontrol CCEs that may be needed on relay link, and 2) the number of datasymbols to be transmitted within the wireless relay transmission frameon the relay link. Based on the two parameters, Pt may be determined insuch a way that the number of symbols that is not used may be minimized.The number of PRB(s) allocated to a relay node on the relay link may beeither fixed or dynamic. If a fixed allocation is used, it may besimpler for the relay node 700 to process the control signalingdetection and processing. If the PRB(s) are dynamically allocated, itmay be more complicated for the relay node 700 to detect and process thecontrol signaling.

FIG. 4 illustrates an example method 400 for transmitting controlsignaling on a wireless relay link. The method 400 may includedetermining a relay resource allocation scheme at block 401, allocatinga control channel resource in a wireless relay transmission frame atblock 402, generating a control signaling at block 408, updating thecontrol signaling at block 406, mapping the control signaling to theallocated control channel resource at block 412, and transmitting thecontrol signaling over the relay link at block 416. The embodiment ofthe method 400 shown in FIG. 4 is for illustration only. Otherembodiments of the method 400 with different sequences of steps could beused without departing from the scope of this disclosure. In an exampleembodiment, the method 400 is performed by the access node 200 in FIG. 1and FIG. 2.

Determining a resource allocation scheme at block 401 may includedetermining a channel resource allocation scheme based on a relay linkstatus, a traffic pattern at the relay node, and the type of theselected wireless relay transmission frame. A dynamic channel resourceallocation scheme may be used if traffic on the relay is very dynamicand control signaling overhead is light. On the other hand, if thetraffic in the relay node is light and does not change frequently, asemi-static allocation scheme may be more suitable. A hybrid allocationscheme may be used for cases where a portion of the traffic may bedynamic and a portion less dynamic.

Allocating control channel resource at block 402 may include identifyingat an upper layer a type of a wireless relay transmission frame, and atotal number of control channel elements allocated for the downlinkcontrol signaling according to the frame type identified. Allocatingcontrol channel resource at block 402 may also include identifying astarting point in the wireless relay transmission frame such as Ps inFIG. 3 and a length of the control channel resource, and sending thestarting point and the length of available resource information to thephysical control module 216 to perform the control signalingtransmission.

Allocating the control channel resource at block 402 may also includeidentifying control channel resource according to a wireless relaytransmission frame type. In one embodiment, allocating the controlresource at block 402 may include identifying either regular MBSFN orzero-control-symbol MBSFN sub-frames. Allocating a regular MBSFNsub-frame may include identifying a starting position of the controlchannel resource in the regular MBSFN sub-frame for the controlsignaling. On the other hand, allocating a zero-control-symbol MBSFNsub-frame may include identifying a different starting position of thecontrol channel resource.

Generating the control signaling at block 408 may take place when thecontents of a control signaling is newly generated in cases such as aconnection setup or the like. Generating the control signaling at block408 may include deciding a control signaling appropriate for the type ofwireless relay transmission frame and generating one or more controlsignaling contents according to the wireless relay transmission frametype. In one embodiment, generating the control signaling at block 408may include generating a channel access grant, a resource allocationscheme, and a resource allocation status indicator, among others. Inanother example embodiment, generating the control signaling at block408 may include generating a resource allocation status when theresource is semi-statically allocated. If the control channel resourcesother than a semi-persistently allocated ones are used by the relaylink, some additional CCEs for the control signaling may be transmittedto indicate the dynamic allocations. Thus generating control signalingat block 408 may include using these additional control CCEs to indicatea resource allocation status. The status may indicate whether additionalresources besides the semi-statically allocated ones are also availablefor the relay node, whether the semi-statically allocated resources arereserved or released by the relay link in the wireless relaytransmission frame, whether some resources other than the semi-allocatedones are allocated to relay node in the wireless relay transmissionframe, and the like.

Generating the control signaling at block 408 may include generatingcontrol signaling based on the control channel resource allocation. Whendynamic resource allocation is used for the relay link, generatingcontrol signaling may include generating downlink resource grants andacknowledgement and negative acknowledgement for Hybrid AutomaticRepeat-reQuest (HARQ) for the downlink physical layer control signaling.HARQ control signaling may support physical layer re-transmission in LTERelease 8 compliant devices by feeding back an acknowledge or a negativeacknowledgement to the transmitting side of the relay link. In a hybridmanner, retransmission of control signaling or payload data may beencoded differently from that of the transmission.

Generating the control signaling at block 408 may also includegenerating a location indicator in the wireless relay transmissionframe. Generating the control signaling may further include generatingthe offset k and the Δk to indicate the location of the controlsignaling where k may indicate the location of first usable symbol andΔk the length of usable symbols in allocated control resource in thewireless relay transmission frame.

Generating the control signaling at block 408 may also includegenerating a second control signaling to support reallocation of channelresources for the relay link that was left unused for a previoustransmission to achieve an improved resource utilization. Some channelresources may not be fully allocated for wireless relay links due tovarious reasons such as dynamic traffic conditions and a specific designof a wireless relay transmission frame format. In one embodiment, asecond control signaling may support a flexible resource allocationthrough resource re-allocation by including a resource grant togetherwith a bitmap to indicate the resource allocations for the subsequentrelay frames. For example, this method may be used to reallocate channelresource for relay link for both the MBSFN sub-frames and thezero-control-symbol MBSFN sub-frames.

Generating the control signaling at block 408 may also includeconfiguring the content of the downlink physical layer control signalingaccording to the characteristic of relay link and the traffic load inthe relay node 700. For example, when little variation occurs on eitherrelay link or traffic load of the relay node 700, the resourceallocation on relay link may stay unchanged. In this case, the downlinkaccess grant may not be transmitted in order to reduce the controlsignaling overhead, and the downlink physical layer control signalingmay be configured to only contain acknowledgement and negativeacknowledgement for the associated uplink process.

Updating the control signaling at block 406 may include adding, deletingor modifying the control signaling contents for a subsequenttransmission. In an example embodiment, previous control signalingcontents may be saved and modified for a subsequent control signaling.The subsequent transmission may use a different resource allocationscheme and a type of wireless relay transmission frame different fromthe current one. For example, the resource allocation scheme may changefrom a semi-static one to a dynamic one. While the current wirelessrelay transmission frame may be a MBSFN sub-frame, the subsequenttransmission frame may be a zero-control-symbol MBSFN sub-frame.

Mapping the control signaling to the allocated control channel resourceat block 412 may include determining a mapping scheme, and mapping thecontrol signaling to the allocated control channel resource in thewireless relay transmission frame. The mapping scheme may be atime-first mapping, a frequency-first mapping, or a multiplexingmapping. In one embodiment, mapping the control signaling at block 412may also include multiplexing the control channel elements for multiplerelay nodes within certain PRB(s) to minimize the resource consumption.In another embodiment, when resource grants are not needed because ofsmall variation in relay link traffic, mapping the control signaling mayinclude multiplexing the downlink control signalings destined formultiple relay nodes in one or more PRB(s) to reduce the controlsignaling overhead. Mapping the control signaling at block 412 may alsoinclude mapping the control signaling in a frequency-first fashion. Thenumber of PRB(s) used and the actual number of control signaling symbolsmay be determined based on the amount of control signaling data andpayload data in such a way that the payload data plus the controlsignaling data on the relay link may make a maximum use of PRBs reservedfor the relay link.

Transmitting the control signaling at block 414 may include encoding thecontrol signaling contents into carrier symbols of wireless relaytransmission frame and transmitting the wireless relay transmissionframe to one or more associated relay nodes. Transmitting the controlsignaling may also involve transmitting part of control signaling intime domain and part in frequency domain. In one embodiment,transmitting the control signaling at block 414 may include transmittingthe zero-control-symbol MBSFN sub-frames, starting from the secondsymbol in a MBSFN sub-frame, thus causing no interference to othercontrol signaling such as an existing LTE Release 8 downlink controlsignaling.

FIG. 5 illustrates an example embodiment 500 of multiplexing multiplecontrol signalings into one wireless relay transmission frame on a relaylink. In one embodiment, to reduce the waste of channel resource, one ormultiple PRBs may be reserved for relay link control, and multiplecontrol signalings intended for multiple relay nodes may be multiplexedwithin the reserved resource PRBs. Multiplexing of control signalingsmay be a time division multiplexing, a frequency division multiplexingor a code division multiplexing. In the example embodiment shown in FIG.5, PRBn is the reserved resource for control signaling. The other PRBs508 in the wireless relay transmission frame, namely, PRBn+1, PRBm,PRBm+1, and PRBm+2 are allocated for carrying payload data. The controlsignalings may be multiplexed, e.g., onto the allocated control channelelements 502 of the PRBn. In this embodiment, a first part of thereserved PRBn, CCE1 502 of two symbols may be allocated for controlsignaling intended for a relay node N1, a second part, CCE2 504 of threesymbols for a relay node N2, and a third part, CCE3 506 of four symbolsfor a relay node N3. The control signalings may be protected by means ofcyclic redundancy check, which may help ensure the correct detection byeach relay node. In this way, a relay node may assume several possiblesizes of the control signaling, and perform blind detection to extractthe control signaling. This flexibility may help the access node 200 fitthe signaling control into an integer multiples of PRBs and avoidresource waste. The control signaling itself may indicate which PRB(s)are used for payload data transmission and in this example, the payloaddata may be mapped to the block of PRBs 508.

FIG. 6 illustrates an example embodiment 600 of updating controlconfiguration on a relay link. The embodiment 600 includes a firstupdate period 602 and a second update period 604. A control signalingmay be updated from time to time to accommodate a condition such as achange of traffic conditions on the relay link. For example, whenconnections are set up and torn down frequently on the relay link and ifthe traffic on the relay downlink is very dynamic, the control signalingmay be updated very frequently. On the other hand, if a traffic patternon the relay link is known to be relatively static, control signalingmay be updated less frequently to reduce the signaling overhead andoptimize the throughput.

In one embodiment, an upper layer module such as the upper-layer controlmodule 214 of FIG. 2 helps determine the first update period k 602 whenthe control signaling is updated. When the upper-layer control module214 decides that there is not a need for an update in the subsequentupdate period k+1 604 for reasons such as a moderate variation intraffic pattern, the control signaling C2 may be configured in such away that it does not contain any resource grant to accommodate thechange in traffic condition. The durations of updating periods may alsovary according to the control signaling contents. For the example shownin FIG. 6, the duration for the updating period k may be much shorterthan that of updating period (k+1) to accommodate the different controlsignaling contents.

FIG. 7 illustrates an example embodiment relay node 700. The relay node700 includes a control module 702, a decoding module 704, and acollection 706 of other modules. The decoding module 704 may beconfigured to receive a wireless relay transmission frame from theassociated wireless access node 200, decode both payload data and thecontrol signaling if the control signaling is present, extract thecontrol signaling from the control channel resource, and execute one ormore control instructions in the control signaling.

The control module 702 may be configured to determine a starting pointof the control signaling if present and the length of the controlsignaling, and pass the starting point and the length to the decodingmodule 704. The collection of other functional module 706 may include apower module, an air interface module, a baseband signal processingmodule, a radio frequency operating module, and a transceiver modulewith one or more antennas.

In one example embodiment, the control module 702 may be configured todefine a control signaling decoding set 302, or a decoding set forshort, as shown in FIG. 3. The decoding set may include a combination ofmultiple decoding rules indexed by relay transmission frame types orother parameters. After decoding a first control channel element, therelay node 700 may extract the “indication information” from the controlchannel resources and identify the ending point of the control channelelements. The relay node 700 may search over all extracted controlchannel elements based on the starting indicator and an ending indicatoras provided in the decoding set. The decoding set may be designed basedon different levels of complexity in correspondence to different levelsof granularity of resource utilization. One example of a simple decodingset include only a maximal number of control channel elements that maybe used for control signaling on the relay link. Different relay nodesmay have different decoding sets to accommodate different trafficconditions of the relay nodes.

In another embodiment, the relay node 700 may receive a regular MBSFNsub-frame on a downlink from an LTE eNodeB. The control signaling mayinclude an access channel grant during a connection setup between theeNodeB and the relay node 700. The decoding module 704 may decode theMBSFN sub-frame, identify the control channels elements, starting fromthe beginning of the portion of the MBSFN sub-frame that was allocatedfor the control signaling, and extract the control signaling from thecontrol channel elements. For example, if the control signaling includesan access grant, the control module 704 may proceed to help set up arequested connection in collaboration with other modules of the relaynode 700.

FIG. 8 illustrates an example method 800 for decoding the controlsignaling, for example, at the relay node 700. The method 800 comprisesdetermining a decoding set at block 802, decoding a control channelelement at block 804, extracting a starting indicator from the decodedcontrol channel element and extracting at least a part of controlsignaling using the starting indicator at block 806, assembling acontrol signaling at block 808, and validating the extracted controlsignaling at block 810. The embodiment of the method 800 shown in FIG. 8is for illustration only. Other embodiments of the method 800 withdifferent sequences of steps could be used without departing from thescope of this disclosure. In an example embodiment, the method 800 isperformed by the relay node 700 of FIG. 1 and FIG. 7.

Determining the decoding set at block 802 may further includedetermining a starting point, a length, and a maximum number of controlchannel elements, among others for the control signaling. Determiningthe decoding set at block 802 may also include considering a level ofcomplexity of decoding operation and a desired level of granularity ofresource utilization. Finer the granularity level of resourceutilization is, more complicated is the control signaling, and thus morecomplicated is the decoding set. Decoding control channel element atblock 804 may include decoding an entire wireless relay transmissionframe and extracting the control channel elements one at a timeaccording to the information in the decoding set. Extracting thestarting indicator at block 806 may further include identifying thestarting indicator based on the information in the decoding set, andlocating the indicator in a decoded control channel element.

Deciding whether the current control channel element is the last oneallocated for the control signaling at block 818 may involve keeping acount of the control channel elements extracted up to this point andcomparing it with the total number of control channel elements allocatedfor the control signaling. If the current control channel element is notthe last one in the allocated resource block, the method 800 continuesdecoding the next control channel element at 804. Assembling the controlsignaling at block 808 may include extracting a part of the controlsignaling from each channel control element and combining parts frommultiple control channel elements, if there is a need. In many cases,the control channel elements may be allocated consecutively and there isnot a need to assemble the parts of the control signaling. However, forsome dynamic allocation of resources and for maximum utilization ofresource, the control channel elements may not be consecutivelyallocated. Validating the control signaling at block 810 may includechecking data integrity of the assembled control signaling using amechanism such as cyclic redundancy check.

A computer program product comprises a computer-readable medium bearingcomputer program code embodied therein for use with a computer or acentral processor, the computer program code comprising code forallocating a control channel resource in a wireless relay transmissionframe on a wireless relay link, code for generating a control signalingbased on at least one of a resource allocation scheme, a status of relaylink and a traffic condition, code for mapping the control signaling tothe allocated control channel resource via one or more of a time-firstmapping, a frequency-first mapping, and a multiplexing mapping, and codefor transmitting the control signaling in the allocated control channelresource on the wireless relay link to at least one associated relaynode.

Another computer program product comprises a computer-readable mediumbearing computer program code embodied therein for use with a computeror a central processor, the computer program code comprising code fordecoding a control channel element from a wireless relay transmissionframe received at a relay node, code for extracting a starting indicatorfrom the decoded control channel element, code for extracting at least apart of a control signaling from the decoded control element using theextracted starting indicator, code for assembling the control signaling,and code for validating the control signaling.

Without in any way limiting the scope, interpretation, or application ofthe claims appearing below, a technical effect of one or more of theexample embodiments disclosed herein may be a wireless relay linkbetween a wireless access node and a relay node that makes use of theunused bandwidth on a wireless transmission frame to carry controlsignaling. Another technical effect of one or more of the exampleembodiments disclosed herein may be a wireless relay control signalingthat is configured to work with existing 3G user equipments as they arewithout changes.

Embodiments of the present invention may be implemented in software,hardware, application logic or a combination of software, hardware andapplication logic. The software, application logic and/or hardware mayreside on a memory, a processor, a computing device or a wirelessnetwork node. If desired, part of the software, application logic and/orhardware may reside on a computing device or a network device, part ofthe software, application logic and/or hardware may reside on anothernetwork device, and part of the software, application logic and/orhardware may reside on a computing device or network device. Theapplication logic, software or an instruction set is preferablymaintained on any one of various conventional computer-readable media.In the context of this document, a “computer-readable medium” may be anymedia or means that may contain, store, communicate, propagate ortransport the instructions for use by or in connection with aninstruction execution system, apparatus, or device.

If desired, the different functions discussed herein may be performed ina different order and/or concurrently with each other. Furthermore, ifdesired, one or more of the above-described functions may be optional ormay be combined.

Although various aspects of the invention are set out in the independentclaims, other aspects of the invention include other combinations offeatures from the described embodiments and/or the dependent claims withthe features of the independent claims, and not solely the combinationsexplicitly set out in the claims.

It is also noted herein that while the above describes exampleembodiments of the invention, these descriptions should not be viewed ina limiting sense. Rather, there are several variations and modificationswhich may be made without departing from the scope of the presentinvention as defined in the appended claims.

What is claimed is:
 1. A receiving device comprising: a wirelessreceiver operable to receive a first signal; a baseband processoroperable to process upper layer control signaling included in the firstsignal, the upper layer control signaling including an indication of alocation of a control resource located in at least one subframe, theupper layer control signaling indicating a start symbol and a number ofsymbols as time resources of the control resource and indicatingphysical resource blocks (PRBs) as frequency resources of the controlresource, the PRBs including at least one control channel element (CCE)designated for the receiving device, and the upper layer controlsignaling indicating a multiplexing scheme for CCEs in the controlresource; the wireless receiver operable to receive a second signal; andthe baseband processor operable to decode the at least one CCE from thereceived second signal using the upper layer control signaling torecover a control channel for the receiving device.
 2. The receivingdevice of claim 1, wherein the at least one subframe is a long termevolution (LTE) subframe.
 3. The receiving device of claim 1, whereinthe receiving device is a user equipment (UE).
 4. The receiving deviceof claim 1, wherein the first signal and the second signal are receivedfrom an eNB.
 5. The receiving device of claim 1, wherein themultiplexing scheme for CCEs in the control resource is a timemultiplexing scheme.
 6. The receiving device of claim 1, wherein themultiplexing scheme for CCEs in the control resource is a frequencymultiplexing scheme.
 7. A method for use in a receiving device, themethod comprising: receiving a first signal; processing upper layercontrol signaling included in the first signal, the upper layer controlsignaling including an indication of a location of a control resourcelocated in at least one subframe, the upper layer control signalingindicating a start symbol and a number of symbols as time resources ofthe control resource and indicating physical resource blocks (PRBs) asfrequency resources of the control resource, the PRBs including at leastone control channel element (CCE) designated for the receiving device,and the upper layer control signaling indicating a multiplexing schemefor CCEs in the control resource; receiving a second signal; anddecoding the at least one CCE from the received second signal using theupper layer control signaling to recover a control channel for thereceiving device.
 8. The method of claim 7, wherein the at least onesubframe is a long term evolution (LTE) subframe.
 9. The method of claim7, wherein the receiving device is a user equipment (UE).
 10. The methodof claim 7, wherein the first signal and the second signal are receivedfrom an eNB.
 11. The method of claim 7, wherein the multiplexing schemefor CCEs in the control resource is a time multiplexing scheme.
 12. Themethod of claim 7, wherein the multiplexing scheme for CCEs in thecontrol resource is a frequency multiplexing scheme.
 13. Anon-transitory computer readable medium that stores a set ofinstructions that when executed by a receiving device causes thereceiving device to: receive a first signal; process upper layer controlsignaling included in the first signal, the upper layer controlsignaling including an indication of a location of a control resourcelocated in at least one subframe, the upper layer control signalingindicating a start symbol and a number of symbols as time resources ofthe control resource and indicating physical resource blocks (PRBs) asfrequency resources of the control resource, the PRBs including at leastone control channel element (CCE) designated for the receiving device,and the upper layer control signaling indicating a multiplexing schemefor CCEs in the control resource; receive a second signal; and decodethe at least one CCE from the received second signal using the upperlayer control signaling to recover a control channel for the receivingdevice.
 14. The non-transitory computer readable medium of claim 13,wherein the at least one subframe is a long term evolution (LTE)subframe.
 15. The non-transitory computer readable medium of claim 13,wherein the receiving device is a user equipment (UE).
 16. Thenon-transitory computer readable medium of claim 13, wherein the firstsignal and the second signal are received from an eNB.
 17. Thenon-transitory computer readable medium of claim 13, wherein themultiplexing scheme for CCEs in the control resource is a timemultiplexing scheme.
 18. The non-transitory computer readable medium ofclaim 13, wherein the multiplexing scheme for CCEs in the controlresource is a frequency multiplexing scheme.